US2373706A - Terpene resins - Google Patents

Description

Patented Apr. 17, 1945 TERPENE RESINS Emil Ott, Wilmington, Del., assignor to Hercules Powler Company, W1

ration of Delaware lmington, Del., a corpo- No Drawing. Application October 2, 1941,

Serial No. 413,301 1 17 Claims. (Cl. 260-80) This invention relates to new resinous compositions of matter and to processes for their production. More particularly, it relates to resins prepared by the copolymerization of a terway tobe taken as being limiting. All parts and percentages are by weight unless otherwise indi- 'cated.

. Examples 1 to 11 incl.

pene with isobutene. 5

It has been found, in accordance with this inry n out t e e p s th foll win vention, that isobutene may be copolymerized adprocedure s employed- ISOblltene was vantageously with various terpenes or mixtures densed in a glass vessel at 70 C. to 50 C. thereof to yield resinous materials having distin- Diffelellt amounts of fl-D dipehtene guishing and useful characteristics not possessed l0 e e with ethyl chloride as reaction sol ent by terpene polymers or by isobutene polymers were then added in a series of 11 separate prepalone. Products having varied characteristics reafatiohs- The reaction mixtures Were a tat sult depending upon whether the mixture submitwhile maintaining the temperature within the ted to polymerizing conditions consists predomiaforesaidlimitficertain of the Preparations nantly of terpenes or is predominantly isobutene. 15 Q b l t fl 'i Was us d as catalysthus, by varying the percentage composition of Where used, it was passed into the reaction mixthe mixture submitted to polymerizing cond t ture over a period of from 0.5 hour to 1 hour with a series of new copolymer resins results which agitation at t In me Of the vary from low meltin point; therlnoplastic resins other examples aluminum chloride was included characterized by their ability to yield highly visas the catalyst n us d; it was added ov r a cous solutions to rubbery solids which show some period of 0.25 h t agitation t to tendency towards thermoplasticity and which are 0 C- After add t of the catalyst, the characterized by their being vulcanizable. tures w re agitated at to f r P The copolymerization of the two materials is riods as indicated in the accompanying table carried out by contacting a suitable admixture and were then diluted with additional ethyl chlowith a polymerization or condensation catalyst, ride with agitation. After the indicated reaction desirably in the presence of an inert solvent. As p o s. t e re ction m xtures were added to 300 catalysts, there may be employed metal halides, parts of 95% ethy a c With agitation- The acids, or activated clays. After the reaction has opol mer r sins w h p e pi t d w re h been allowed to proceed to the point where there oughly sh Wi h additional 95% ethyl a100- has resulted a substantial yield of copolymerized hol and then dried. The dipentene employedin product, the reaction mixture is treated to rethe examples w s a commercial grade and 00!!- move the'catalyst. Thereafter, unreacted contained pp o y dipentene and stituents and any inert solvent present is' repara-cymene. The para-cymene was unreactive moved. I under the conditions employed. Further details -There follow'several specific examples which of the reaction conditions and a description of illustrate particular embodiments of the princithe resulting copolymer resins are given in the ples of this invention which, however, are in no following tabulation:

- Bcac- Ethyl Drop Exg gple Tel-pen :22: 233 Catalyst 31%: 5 32:551 mlilgi g Properties Parts Parts Parts Parts Home C.n0 H d b I 1 v 51 53233 82251 I ""i'TS' %Z i .5SI.IIII i i8 100' ri id tiittie eggiiy'mer, slightly flexible,

' slightly extensible and retractable. p-pinene (l0) 5 l5 BF:.(4) 1.0 18 65 Flexible, somewhat tacky, slightly extensible and retractable. p-plnenel0)- 5 25 A101; 1.4).." 0.25 2o 20 Do. fl-pinene 5)-.... 10 25 A101; (1.6) 0.25 20 Flexible, tacky, extensible, retractable,

' thermoplastic.- fl-pinene (5). l0 15 1.5 22 Do. B-pinene (1.5)..-. 13.5 25 0.25 20 Rubber-like product, tendency to be thermoplastic harder than isobutene polymer. 1o 25 AlCl;(l.5)..-.- 0.25 20 Rubber-like product. 9- Dipentene (l0) 20 A101; (1) 0. 50 20 Hard, brittle polymer. l0. Dlpentene (l0). 5 20 AlChO) 0. 50 sofgklalexible, slightly extensible and retractll Dipentene (5)...- 10 20 A101; (1) 0. 50 20 Flexible, tacky, extensible and retractable.

Example 12 ter solution,maintained at 30 C., were added 6.3 parts of the aluminum chloride solution, and

the reaction mixture was held at C. to

C. for 7 hours. The reaction mixture was then diluted with 150 parts of acetone containing 1 part of water to hydrate the catalyst; The'precipltate was redissolvedin benzene and 'reprecipitated with acetone. The resulting copolymer was colorless and flexible as compared with solid polymerized allo-ocimene. It had a thiocyanate value As terpenes useful in preparing the copolymers, any terpene hydrocarbon having the empirical formula CmHm, or a mixture thereof, may be used.

about 30 C., and the reaction period between about-M, hour and about 24 hours. with the use of an acid catalyst, it is Preferred to employ a catalyst to reactant ratio between about 0.05 and about 1.0, a reaction temperature between about 10 C. and about 100 C., and a reaction period between about 2 hours and about 24 hours. When an activated clay is employed as the catalyst, it

is preferred to use a catalyst to reactant ratio betweenabout 0.05 and about 0.50, a reaction tem- These include acyclic terpenes, such as, myrcene.

ocimene, allo-ocimene, cryptotaenene, etc.; monocyclic terpenes, such as, dipentene, u-terpinene, p-terpinene, gamma-terpinene, terpinolene, sylvestrene,a-phellandrene, p-phellandrene, origancue, the pyronenes, etc.; bicyclic terpenes, such as,'a-thujene, p-thujene, sabinene, the carenes, a-pinene, p-pinene, camphene, bornylene, a-fenchene, p-fenchene, gamma-fenchene, etc.

Inplace of pure terpenes or their synthetic mixtures, naturally-occurring terpene .mixtures may be employed, as for example, wood or gum turpentine. Other fractions containing crude mixtures of terpenes obtained as a result of the recovery of oleoresinous materials from pine wood may be employed, as for example, "Solveno, a mixture containing the monocyclic terpene hydrocarbons, terpinene, terpinolcne and di- I pentene. Other terpene mixtures obtained in the heat isomerization of aand/,or p-pinene' may be employed. For example, 'pyrolyz'ed ii pinene which may contain as much as 40% allo-ocimene along with substantial amounts (ifs-P1118118, dipentene, etc., or pyrolyzed p-pinene which contains appreciable amounts of myreene, etc., are useful. Terpene mixtures obtained, in the synthesis of ethers and alcohols from aand pinene may also be used. v

In the examples the useof certain catalysts is shown. Others may be utilized. h s. a polymerization catalysts, there may be employed the metal halides, such as, borontrifluoride and its molecular complexes-with ethers andaclds, ti-

taniumchloride, ferric chloride, and the halides I of metals whose hydroxides are amphoteric, as aluminum chloride, stannic chloride, zinc chloride, etc.; acids. such as, hydrofluoricacid, fluoroboric acid, polybasic mineral acids, as orthophos- 'phoric acid, tetraphosphoric acid, sulfuric acid,

etc., acyl sulfuric acids, as acetyl sulfuric acid, alkyl sulfuric acids, as ethyl sulfuric acid, paratoluene sulfonic acid, etc.; and activated clays, such as, fullers earth, diatomaceous earth, alumina, bauxite, synthetic magnesium silicates, etc.'

For the acid catalysts,- certain anh'ydrides'. as phosphorus pentoxide, etc., may be equivalently employed. The activated clays will desirably be calcined at temperatures of, for example, from 100 C. to 500 C. prior touse.

' In the process of preparation of the copolymers, the catalyst to reactant ratio will generally vary between about0.001 and about 1.0. The operableltemperature will vary between about-40 C. and about 200 C.', and the operable reaction period' will vary between about i and about 400 proved by utilizing terpenes which have been disperature between about C. and about 200 C., and a reaction period between about 2 and about 16 hours. The metal halide catalysts, particularly aluminum chloride and boron trifluoride, in conjunction with a halogenated hydrocarbon solvent, as ethyl chloride, ethylene chloride, etc.'are preferred where solids and highly viscous liquid copolymers are desired.

As indicatedby the examples, varying ratios of terpene to isobutene may beemployed. However, in the production of copolymers from predominantly terpene mixtures, it is preferred to employ between about 5% and about 50% by weight of isobutene 0n the basis of the terpene. On the otherhand, where rubbery copolymers are desired which are characterized by their being sufficiently unsaturated to enable vulcanization, it is preferred to employ between about 1% and about 10% by weight of terpene on the basis of the isobutene.

In the preparation of the'copolymer resins by the processes of the examples, a solvent for the reactants is desirably employed. As solvents, any organic liquid which is inert to the reactants and catalyst may be employed. Aliphatic hydrocarbons, such as, gasoline, petroleum naphtha, butane, pentan'e, etc.; aromatic hydrocarbons, such as, benzene, toluene, xylene, etc.; cyclic hydrocarbons, suchas, cyclohexane, decahydronaphthalene, etc.; esters, such as, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, nbutyl acetate, etc.; halogenated hydrocarbons, such as, chloroform, ethylene dichloride, carbon tetrachloride, trichloroethylene, ethyl chloride, methylene chloride, etc., may be employed.

Following the reaction period,- the reaction mixture is treated to recover the-'copolymerlzation'product. The examples illustrative of certain methods of recovery. Qthers are applicable. Thus, where a metal halideor acid catalyst has been employed, it may be removed by washing the reaction mixture with water or an aqueous alkali or an aqueous inorganic acid. Following the aqueous alkali or acid wash, it is desirable to wash with water to remove all traces of alkali or acid. Furthermore, traces of' dissolved catalyst and/or catalyst-copolymer complexes may be removed after water-washing by treatment with a suitable adsorbent, as Filter-'- Cel, bauxite, activated alumina, activated magnesium silicate, fullers earth, activated carbon, etc. Finally, the solvent, if one has been used,

and any unreacted constituents will be removed, I desirably, by vacuum distillation using a final bath temperature of to 220 C.

The color of the final products'may be imtilled from caustic. Also, the use of an inert atmosphere, such as, CO2, N2, etc., during the reaction yields pale-colored products. Other refining agents-which may be employed include the adsorbents hereinbefore mentioned, also selective solvents, such as, furfural, furfuryl alcohol, phenol, etc. If desired, the copolymer resins obtained in accordance with the processes described herein may be subjected to vacuum distillation to remove volatile copolymers, leaving copolymer residues having higher melting points than the initial copolymerization product. i

The copolymers resulting from the copolymerization of terpene-isobutene mixtures which are predominantly terpene are characteristically soft resinsi. e., they have lower melting points than do the polymers formed upon polymerization of the terpene itself.- Quite unexpectedly, however, it has been found that these resinous copolymers although they have lower melting points exhibit increased viscosities as comparedwith the corresponding terpene polymers. The copolymer resins themselves show their increased viscosity, also their solutions in inert solvents. more, copolymers prepared from isobutene-terpene mixtures which are predominantly terpene possess an inherent fiexibility which is lacking in terpene polymers. The brittleness of such terpene polymers makes them somewhat undesirable for use in protective coatings unless in combination with other resins contributing the desired flexibility. subject to the disadvantage; they furthermore exhibit a tendency towards extensibility and retractability.

The copolymers which result from merization of terpene-isobutene mixtures which are predominantly isobutene are rubbery compositions which tend to be thermoplastic. These copolymers are distinctly interesting in that they are unsaturated and can be vulcanized. The rubbery polymers obtained from the polymerization of isobutene alone do not possess the advantage and hence their uses are limited. By employing minor proportions of a desired terpene in conjunction with isobutene, rubber-like materials result which can be easily vulcanized, hence overcoming one of the serious limitations in the use of the prior art polymers.

The solubility characteristics of the copolymer resins of this invention are. such that they can be dissolved in common solvents, such as, benzene, toluene, gasoline, chlorinated hydrocarbons, etc. They are only slightly soluble in solvents, such as, ethyl alcohol, acetone, ethylene glycol, etc.

The copolymer resins prepared in accordance with the processes described herein, as a consequence of their good film-forming characteristics,

are useful in the preparation of coatings for various surfaces, as wood', glass, paper and metal. Films of these resins are strong and flexible and adhere well to the aforesaid surfaces. The resins are also useful in the formulation of adhesives. In the form of pigmented compositions, they make excellent paints and lacquers for wood, metal, paper, etc. 'Unpigmented solutions or emulsions of the resins are suitable for impregnating paper, textiles, wood, etc., to contribute strength, toughness, flexibility, etc., thereto.-

It will be understood that wherever in this specification reference is made to the melting point of a resinous material, a meltingpoint as determined by the Hercules drop method is contemplated.

Further- The copolymer resins are not.

the copolyof a terpene and isobutene at a temperature between about '70 C. and about 200 C., said mixture containing at least 5% by weight of isobutene on the basis of the terpene.

2. The process of preparing a solid copolymer of a, terpene and isobutene which comprises treating a mixture of a terpene and isobutene dissolved in an inert organic solvent with a catalyst capable of forming a solid copolymer of a terpene and isobutene at a temperature between about C. and about 200 C., said mixture containing at least 5% by weight of isobutene on the basis of the terpene.

3. The process of preparing a solid copolymer of a terpene and isobutene which comprises treating a mixture of a. terpene and isobutene dissolved in an inert organic solvent with an aluminum chloride catalyst at a temperature between about 70 C. and about 30 C., said mixture containing at least 5% by weight of isobutene on the basis of the terpene.

5. The process of preparing a solid copolymer of a monocyclic terpene and isobutene which' comprises treating a mixture of amonocyclic terpene and isobutene dissolved in an inert organic solvent with an aluminum chloride catalyst at a temperature between about 70 C. and about -30 C., said mixture containing at least 5% by weight of isobutene on the basis of the terpene.

6. The process of preparing a solid copolymer of a terpene and isobutene which comprises treating a mixture of a terpene and isobutene dissolved in an inert organic solvent with an acid catalyst capable of forming a solid copolymer of a terpene and isobutene at a temperature between about 10 C. and about 100 C., said mixture containing at least 5% by weight of isobutene on the basis of the'terpene.

'7. The process of preparing a solid copolymer of a terpene and isobutene which comprises treating a mixture of a terpene and isobutene dissolved in an inert organic solvent with an activated clay catalyst capable of forming a solid copolymer of a terpene and isobutene at a temperature between about 80 C. and about 200 C., said mixture containing at least 5% by weight of isobutene on the basis or the terpene.

(ill

' 8. The process of preparing a solid copolymer of beta-pinene and isobutene which comprises treating a mixture of beta-pinene and isobutene dissolved in ethyl chloride with analuminum.

chloride catalyst at a temperature between about -'10 C. and about -30 C., said mixture con-" ing a mixture of a terpene and isobutene with a catalyst capable of forming a-solid copolymer of a terpene and isobutene at a temperature between about '10 C. and about 200 C., said mixture containing at least 5% by weight of isobutene on the basis of theterpene.

10. A solid copolymer of a. terpene and isobutene formed by a process which comprises treating a mixture of a terpene and isobutene dis solved in an inert organic solvent with a catalyst capable of forming a solid copolymer of a terpene and isobutene at a temperature between about 70 C. and about 200- C., said mixture containing at least 5% by weight of isobutene on the basis of the terpene.

11. A solid copolymer of an acyclic terpene and isobutene formed by a process which comprises treating a mixture of an acyclic terpene and isobutene dissolved in an inert organic solvent with a catalyst capable of forming a solid copolymer of an acyclic terpene and isobutene at a temperature between about -70 C. and about 200 C., said mixture containing at least 5% by weight of isobutene on the basis 01' the acyclic terpene.

12. A solid copolymer of allo-ocimene and iso-' butene formed by a process which comprises treating a mixture of allo-ocimene and isobutene dissolved in an inert organic solvent with a catacopolymer of a monocyclic terpene and isobutene at a temperature between about 70 C. and about 200 C., said mixture containing at least 5% by weight of isobutene on the basis or the monocyclic terpene.

14. A solid copolymer of dipentene and isobutene formed by a process which comprise treat- 1118 .a mixture of dipentene and isobutene dissolved in an inert organic solvent with a catalyst capable of forming a solid copolymer of dipentene and isobutene at a temperature between about 70' Cjand about 200 C., said mixture containing at least 5% by weight of isobutene on the basis of the dipentene;

15. A solid copolymer of a bicyclic terpene and isobutene formed by a process which comprises treating a mixture 01' a'bicyclic terpene and isobut'ene dissolved in an inert organic solvent with a catalyst capable of forming a solid copolymer of a bicyclic terpene and isobutene'at a temperature between about --70" C. and about 200 C.,

.said mixture containing at least 5% by weight of isobutene on the basis of the bicyclic terpene.

16. A solid copolymer of a pinene and isobutene formed by a process which'comprises treating a mixture of a pinene and isobutene dissolved in an inert organic solvent with a. catalyst capable of forming a solid copolymer of a pinene and isobutene at a temperature between about 70 C. and about 200 C., said mixture containing at least 5% by weight of isobutene on the basis of the pinene.

' 17. The process of preparing a solid copolymer of a terpene and 'isobutene which comprises treating a mixture of a terpene and isobutene dispolymer with a refining agent.

solved in an inert organic solvent with a catalyst capable of forming a solid copolymer of a terpene and isobutene, at a temperature between about 'l0' 0. and about 200%., said mixture containing at least 5% by weight of isobutene on the basis otthe terpene, and treating said solid c0-